Excavator.



W. G. LAWRENCE.

EXCAVATOR.

APPLICATION FILED OCT. 3, 1912.

Patented Jan. 25, 1916.

THB COLUMBIA PLANOGRAPH co.. WASHINGTON, D C

lUNITlE T v 1:. are on.

WILLIAM G. LAWRENCE, O1? MARTINTON, ILLINOIS, ASSIGNOR T0 FREDERICK G.

AUSTIN, OF CHICAGO, ILLINOIS.

Excavation.

Specification of Letters Patent.

Patented J an. 25, 1916.

Application filed October 3, 1912. Serial 1%. 723,656.

tain new and useful Improvement in vators, of which the following 1S2). spec1fication.

My invention relates to excavating. machinery of that character in which the work is done by a bucket which travels back and forth on a runway, and in which the load is discharged from the bucket by movement of the back or end wall thereof, relative to the body of the bucket, the said runway being adapted to determine the cross sectional contour of the ditch.

Generally stated, the object of my invention is to provide a novel and improved excavator of the foregoing general character.

A special object is to provide an improved construction and arrangement whereby the bucket discharges while moving forward, as distinguished from previous constructions in which the bucket discharges after it reaches the limit of its forward motion,

or in which the bucket discharges after it reverses its movement and starts back in the opposite direction.

Another object is to provide a novel and improved construction whereby a bucket of this character is capable of discharging its load by movement of the back or end wall thereof faster than the body of the bucket, which may be accomplished, it will be seen, by accelerating the movement of the end wall, after it reaches a certain point in the path of travel of the bucket, or by retarding the forward movement of the body of the bucket, leaving the said back or endwall traveling at the normal rate of speed, whereby the load is fully discharged by the time the bucket reaches the limit of its forward movement.

It is also an object to provide certainciples of my invention. Fig. 2 is a longitudinal section of the said bucket, on a larger scale, showing one side of the'runway broken away for convenience of illustration. Fig. 3 is a plan of the bucket and adJacent portions of the runway on the same scale as Fig. 2. Fig. 4- is an end view of the construction shown in Fig. 3.

As thus illustrated, my invention comprises an excavator body A of any suitable known or approved construction adapted to extend across the ditch and rest upon the bank at each side thereof. The runway B is mounted to move up and down on the said body of the excavator, and is of a shape to determine the cross-sectional contour of the ditch, said runway being of any suitable construction. The bucket 0 travels back and forth on the said runway, being operated by the cables 0 and 0 which are attached to opposite ends of the said bucket,

and whichare operatedrespectively by the drums c and c on the body.

It will be understood that one drum pulls the bucket in one direction, and that the other drum then pulls the bucket in the op posite direction. For this purpose any suitable means can be employed for controlling said drums.

The said bucket is constructed in accordance with my invention, as shown more clearly in Figs. 2 to 4:, inclusive, and comprises a body 0 mounted on the wheels 0 that travel on the said runway. The said bucket is open at the opposite ends thereof, and its front upper wall 0 is provided at opposite ends thereof with earsc and 0 to which the ropes or cables 0 and c are secured respectively. The runway is provided at opposite ends thereof with cross bars I), such as the ones shown in Figs. 2 to 4, inclusive, and the bucket is provided with anendless chain D having a link d for engaging saidcross bars. The said link belt or chain travels over sprocket wheels (Z mounted in bearings (Z2 on topof the bucket at points outside of the aXes of the wheels 0 and the lower portion of said link belt or chain is connected in any suit able manner to the movable back or end wall E of saidbucket. The inner orunder side of" the top wall 0 is provided with parallel'longitudinal guides 0 and the said surface of the wall and against the outer edges of'the guides 0 whereby the surface thereof.

said back or end wall is maintained in po- The upper porsition within the bucket. tion of the said chain or lmk belt is prevented from sagging by a fiat guide or support 0 9 secured to the top of the bucket and L, disposed a short'distance above the'upper By meansof the nuts 0 on the meeting end portions of the chain D, the latter can be tightened or adJusted to suit the requirements. 7

The mode of operation is as follows: The bucketis adapted to fill by movement thereof in either direction, being open at its opposlte ends, and being what is ordinarily knownas a'two way bucket. Assuming thatv the said bucket has, filled, and is moving toward the right, the link d willstrike the cross bars 6, in themanner shown in Fig. 2, some time before the bucket reaches the limit of its forward motion. This does not stop the bucket,

as the pull on the rope or cable 0 continues,

and the result is that the link (Z stands still, thus causing the back or end wall E to move forward relative to the bucketthat is to say, the speed of the said back or end wall is accelerated, whereby the load is expelled from the bucket.

It will be seen that this automatic discharge of the load commences at a time while the bucket is still moving forward, and not after the bucket stops moving, whereby the discharge is progressive and of a character to distribute the load over a wider area, the last portion of the load being expelled at about the time that the bucket stops moving forward. Consequently, and as shown, an excavator of this kind is capable of discharging the load in such manner that the spoil bank does not have a-sharp ridge at the top thereof, but to the contrary is somewhat flat on top, or in any event broader and more level on top than heretofore. This is an advantage, as will be readily understood, in the subsequent handling ofthe dirt in the spoil bank, as the more leveltop of the bank facilitates the work.

Furthermore, it will be seen that the discharge of the load is accomplished without shock or jarfthat is tosay, without any severe bumping, and without danger of breaking the bucket, asjthe attendant can observe when the link (Z strikes the cross bar Z), and thus'be prepared to shut off the power by the time the bucket reaches the limit of its forward motion. The nuts F of the bolts which hold thebearings d in place upon the bucket serve as stops for limitingthe back and forth motion of the back or end wall E, the said back or end wall being provided at its upper edge wih flanges 6 which engage the said nuts in the manner shown in Fig. 2.

The shoes or sliding portions 0 are con-' nected with the back or end wall'E by means .the limit of its forward motion, and in this way the load is entirely discharged by the time thebucket stops moving, whereby the load is scattered over a greater area than heretofore, for the purpose explained. Also, it will be seen that the draft or pull is on the body of the bucket, and not on the back or end wall, whereby the latter is not liable to pull out or become broken or disarranged.

\Vhat I claim as my invention is:

1. An excavator comprising a runway, a bucket traveling thereon, means for operating-said bucket, whereby the bucket moves forward and back on said runway, without turning around, the said bucket having a movable back or end wall, a, track on which the said back or end wall slides, and meohanism whereby said back or end wall expels the load while the bucket is moving forward.

2. 'An excavator comprising a runway, a bucket traveling thereon, means for operating said bucket, the said bucket having a movable back or end wall, mechanism wl1ereby said back or end wall expels the load while the bucket is moving forward, said mechanism including a gear connection between the bucket and end wall, and means on the runway for engaging said gear connection to cause the said back or end wall to move faster than the body of the bucket.

3. An excavator comprising a runway, a bucket traveling thereon, means for operating said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward, said mechanism comprising a sprocket chain connection carried by the bucket and connected with said back or end wall, and means on the runway for engaging said sprocket chain connection, whereby the said back or end wall is caused to move faster than the bucket.

4. An excavator comprising a bucket, a runway upon which the bucket travels back and forth, mechanism for causing the bucket to discharge the load gradually, from the front end thereof, while moving forward and before reversal of movement thereof, said mechanism including a wall movably mounted within the bucket, a track on which said wall slides, and means whereby in dumping the load thesaid wall travels fas ter than the body of the bucket.

5. An excavator comprising a runway, a bucket traveling thereon, ing said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward,

means for operatsaid mechanism including a sprocket chain attached to said back or end wall, and sprockets for said chain, disposed at opposite ends of said bucket.

6. An excavator comprising a runway, a bucket traveling thereon, means for operaing said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward, said mechanism including a belt connection between the bucket and said back or end wall, and means for holding a portion of said belt stationary, while the bucket is moving forward.

7. An excavator comprising a runway, a bucket traveling thereon, means for operating said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward, said mechanism including an element mounted to reciprocate back and forth on top of the bucket, and stationary means for engaging said element.

8. An excavator comprising a runway, a bucket traveling thereon, means for operating said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward, said mechanism including a track on top of said bucket, an element which slides back and forth on said track, and stationary means for engaging said element.

9. An excavator comprising a runway, a bucket traveling thereon, means for oper ating said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward,

in combination with means for causing a like operation of the said back or end wall while the bucket is moving in the reverse direction.

10. An excavator comprising a runway, a bucket traveling thereon, means for operating said bucket, the said bucket having a movable back or end wall, mechanism whereby said back or end wall expels the load while the bucket is moving forward, said bucket having a mouth at each end, and

said back or end wall being operative to' expel the load from either mouth, whereby the bucket loads through one mouth while moving forward, and through the other mouth while moving backward, together with means at opposite ends of said runway for operating said mechanism.

11. An excavator comprising a traveling bucket provided with a movable wall for expelling the load, a movable element on said-bucket, a flexible connection between said element and wall, and means for engaging said element to operate said wall.

12. In an excavator, a traveling bucket, mechanism whereby the bucket expels the load gradually from the forward end thereof, while moving ahead, including an ejector therein, movable faster than the bucket, means for automatically producing said movement of the ejector, all carried on the bucket movable bodily therewith, a stop for engaging said mechanism, and a structure for supporting said stop, upon which said bucket is mounted to travel.

Signed by me at Chicago, Illinois, this 30th day of September 1912.

WILLIAM G. LAWRENCE.

WVitnesses:

H. KNUDSON, J. NORBY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

